If we had an award for most improved in the SSD space, it would have to go to Samsung. When we first encountered Samsung MLC drives a few years ago they were pretty bad. Prices were high and performance was low. Samsung offered no end-user upgradable firmware for those early drives either, although that was eventually rectified. The first Samsung MLC SSDs were reliable, they just weren't worth the money when you had much better options from companies like Intel.

Samsung had all of the right pieces for success however. Like Intel, Samsung made its own NAND, controller and wrote its own firmware. Unlike Intel, Samsung stuck to the vertically integrated formula.

I remember arguing with Samsung engineers a few years ago about the importance of random IO performance compared to sequential speed. I remember feeling like they were making the same mistake that all SSD makers were making back then: heavily prioritizing sequential IO when it was a failure to deliver good random IO performance as well that really hurt SSD adoption. Although the first Samsung SSDs weren't very good, they got better over time. While the first generation couldn't be recommended, the Samsung SSD 470 could. It still wasn't our favorite drive, but it finally brought performance up to a reasonable level. Last year's 830 release showed us that Samsung woke up. Today, Samsung is adding two new members to the family: the Samsung SSD 840 and the 840 Pro. The former is the first productized consumer SSD to use Samsung's 21nm 3-bit-per-cell MLC (aka TLC) NAND, while the latter is Samsung's new flagship drive using 21nm 2bpc MLC NAND.

Unfortunately we don't have samples of the unique TLC SSD 840, just the MLC 840 Pro. Despite the use of TLC NAND, Samsung claims the vanilla 840 should offer similar performance to the current 830. Samsung also claims that endurance should be reasonable for consumer workloads.

The 840 Pro should be tangibly faster than the 830 thanks to a new controller, new firmware and new NAND:

Samsung SSD 840 Pro vs 830

Samsung SSD 830 (256,512GB)

Samsung SSD 840 Pro (256,512GB)

Sequential Read

520MB/s

540MB/s

Sequential Write

400MB/s

450MB/s

Random Read

80K IOPS

100K IOPS

Random Write

36K IOPS

78K IOPS

Active Power Use

0.24W

0.068W

Idle Power Use

0.14W

0.042W

While the 830 used Samsung's 27nm MLC NAND, the 840 Pro uses Samsung's latest 21nm MLC NAND. The move to 21nm will eventually drive NAND pricing lower, although today Samsung expects price parity between the TLC equipped 840 and the old MLC 830. The 840 Pro should sell for a 25 - 30% premium over the current 830.

Samsung SSD 840 Pro Pricing

64GB

128GB

256GB

512GB

Samsung SSD 840 Pro

$99.99

$149.99

$269.99

$599.99

The move to 21nm is also coupled with a move to a 400Mbps Toggle 2.0 NAND interface. Block and page sizes remain the same for 2bpc MLC 21nm NAND, and maximum capacity per die is still 8GB. Although beyond the scope of this article, 3bpc TLC 21nm NAND sees 50% slower program/erase times compared to the 2bpc MLC 21nm NAND.

Both the 840 and 840 Pro use Samsung's 4th generation SSD controller. Samsung's MAX controller was used in the SSD 470, its successor, the MBX controller, wasn't used in retail drives, while MCX debuted in the 830 and MDX is in the 840/840 Pro. The basic architecture of the controller hasn't changed. Internally there are three ARM9 cores now running at 300MHz. Update: Samsung originally listed ARM9 cores but has since told us that there are three ARM Cortex R4s inside of the new MDX controller.

The MDX controller features a hardware AES-256 encryption engine that's managed using a system BIOS password like most other drives in this class.

The MDX controller is paired with 512MB of LPDDR2-1066 in the Samsung SSD 840 Pro, doubling up the DRAM used in the 830 as well as increasing bandwidth to DRAM by 33%:

SSD DRAM Size Comparison

Drive

Controller

DRAM Size

DRAM Speed

Corsair Neutron GTX

LAMD LM87800

256MB

DDR2-800

Crucial m4

Marvell 88SS9174

256MB

DDR3-667

Intel SSD 320

Intel X25-M G3

64MB

SDR-166

Intel SSD 520

SandForce SF-2281

0MB

-

OCZ Vertex 4

Indilinx Everest 2

512MB/1GB

DDR3-800

Samsung SSD 830

Samsung MCX

256MB

DDR2-800

Samsung SSD 840 Pro

Samsung MDX

512MB

LPDDR2-1066

The 840 Pro will be available in 64 - 512GB capacities. Although the controller supports up to 1TB of NAND, Samsung believes that the ultra-high-density NAND required to hit 1TB is too cost prohibitive at this point. Spare area is set at around 7% by default, although users will be able to adjust it via Samsung's SSD Magician utility. The vanilla 840 on the other hand will boast more spare area (likely to help manage endurance on the TLC NAND) and will launch at 120GB, 250GB and 500GB capacities as a result.

The 256GB SSD 840 Pro features 8 x 32GB NAND devices on the front of the PCB and nothing on the back

The 840 comes with a 3 year warranty compared to a 5 year warranty on the 840 Pro.

The 840 Pro drops the brushed aluminum look of the 830 for slightly more modern, flat black styling. The drives will be available in a 2.5" 7mm form factor, similar to the 830.

Samsung SSD 840 Pro (top) vs. Samsung SSD 830 (bottom)

Both drives will be available on October 15th, however in advance of the release Samsung provided us with a beta sample for review. We were only able to get a 256GB 840 Pro initially but we've already asked Samsung for additional capacities. The other bad news is after running through our client test suite and preparing the drive for a run through our enterprise suite, our pre-production sample died. This isn't the first time we've had an SSD die during our test process, pretty much every company has seen a failure during one of our reviews, but despite Samsung's excellent track record even it isn't immune from early issues. These drives are a few weeks away from retail and Samsung will be getting our sample back this week to figure out what went wrong.

Update: My replacement 840 Pro also died, I have shipped both drives back to Samsung and are waiting for their analysis of the failures.

I'm seeing them in stock all the time now. I was just about to order one when I saw that updated comment about both samples dying. I was patting myself on the back for not jumping in on the bleeding edge and had decided that now the technology is mature enough and reliable plus the comfort of the 5 yr warranty so time to dive in....

Of course, 2 samples dying, while a bit off putting, is far from statistically significant.

When I enable the HD Password setting in my BIOS, as soon as I reboot the laptop and enter the password when prompted I get a disk error message. I have tried this on two different ThinkPad laptops and with two different SSD 840 Pro Drives.

Luckily, I can go back into BIOS, enter the password I created and remove the password and the drives show up fine. I read that some OCZ SSD drives had issues with BIOS passwords and that was fixed with a SSD firmware update. I don't know if this has a similar issue with my ThinkPads.

I talked to Samsung support, though they basically said it should work and they have not heard of any issues. I don't think many users actual enable the BIOS HD Password (and therefor enable the encryption protection).

I don't think there is really anything I could be doing wrong *though I would be happy is someone could tell me I am), since it is a simple matter of just enabling the password in BIOS. I know I am using the assigned password and that the drive accepts it, since it lets me past the prompt when I put the correct password. The problem is that at that point the drive looks invalid to BIOS. It doesn't just skip the drive, I get a "Error 0200 Failure Fixed Disk 0" error and my only option is to enter BIOS.

I have an old conventional drive with hardware FDE that works fine on the same laptop.

So, again, I am just wondering is this is working for anyone else?Reply

Beware of these drives. They are not reliable. I have 2 piece of this. They can't be used in the RAID Array. They freeze in the range 2-48 hours and become unavailable to next computer power off/on cycle. Samsung refuses any support to correct this bug. Samsung support said."Samsugn does not provide RAID support regarding the units. The units can be placed in the array however it is at the users discretion."Reply